The present invention relates to the field of distributed computing, and more particularly to Web services.
Web services represent the leading edge of distributed computing and are viewed as the foundation for developing a truly universal model for supporting the rapid development of component based applications over the World Wide Web. Web services are known in the art to include a stack of emerging standards that describe a service oriented, component based application architecture. Specifically, Web services are loosely coupled, reusable software components that semantically encapsulate discrete functionality and are distributed and programmatically accessible over standard Internet protocols.
Conceptually, Web services represent a model in which discrete tasks within processes are distributed widely throughout a value net. Notably, many industry experts consider the service oriented Web services initiative to be the next evolutionary phase of the Internet. Typically, Web services can be defined by an interface such as the Web services definition language (WSDL), and can be implemented according to the interface, though the implementation details matter little so long as the implementation conforms to the Web services interface. Once a Web service has been implemented according to a corresponding interface, the implementation can be registered with a Web services registry, such as Universal Description, Discover and Integration (UDDI), as is well known in the art. Upon registration, the Web service can be accessed by a service requester through the use of any supporting messaging protocol, including for example, the simple object access protocol (SOAP).
Referring to FIG. 1, a traditional Web services server 110 includes a servlet 140 disposed within a Web container 120 as a listener for a Web service request 160A from a Web services client 130 and to provide a response 160B to the Web services client 130. When the request 160A is received in the servlet 140, the message content of the request 160A, along with reflection logic, are used to create the target object of the message, and to select the correct method in an instance of business logic 150 on the object. Parameters to the method on the target object further are created using the encoded form of the message along with the methods of the reflection interface. Thus, the conventional Web services model couples the client interface to the server implementation of the service.
The flow of control, once the message 160A has been delivered to the servlet 140 is as follows:                1. Message delivered to the servlet.        2. Servlet determines the name of the class to service the message.        3. Servlet creates an instance of the class.        4. Servlet determines the name of the method to invoke on the class.        5. Servlet creates the parameters to the method from information in the message.        6. Servlet invokes the method passing the parameters created from the message.        7. Method returns with results.        8. Servlet encodes the results similar to the parameters sent in the message.        9. Servlet responds with the response message.        